This is really perplexing to me. I recently update the firmware in my 7D MK2 to v1.1.0 from 1.0.5. Absolutely no issues with any of on Canon lenses or combinations of Canon 1.4TC and 70-200 and 100-400. However, this morning I decided to visit a local store and try a Sigma 150-600 C and a Tamron 150-600 G2.
Both lenses were new, out of unopened boxes. Both lenses took 3-4 images then the camera rose with a "card2" message on the top LCD screen and a "writing to card" on the back screen. No problem to clear that, just popped the battery out and put it back in. We tried several different SD cards and the same thing happened every time. Even went as far as trying a Sigma 150-600 S as well as a V1 Tamron.
I called Canon and they just told me to call Sigma and Tamron. In reality, they are right because they cannot really deal with what seems to be a lens issue.
Again, everything works properly with my Canon lenses.
Has anyone that has update to 1.1.0 ran into this issue and if so, did you find a solution/ Is there something that I am not aware of happening?
thanks for the time taken to read and reply.